In contrast to the impact of elevated progesterone on endometrial receptivity, the data on whether increased progesterone levels affects the quality of embryos is still limited. This study retrospectively enrolled 4,236 fresh in vitro fertilization (IVF) cycles and sought to determine whether increased progesterone is associated with adverse outcomes with regard to top quality embryos (TQE). The results showed that the TQE rate significantly correlated with progesterone levels on the day of human chorionic gonadotropin (hCG) trigger (P = 0.009). Multivariate linear regression analysis of factors related to the TQE rate, in conventional IVF cycles, showed that the TQE rate was negatively associated with progesterone concentration on the day of hCG (OR was -1.658, 95% CI: -2.806 to -0.510, P = 0.005). When the serum progesterone level was within the interval 2.0–2.5 ng/ml, the TQE rate was significantly lower (P <0.05) than when the progesterone level was < 1.0 ng/ml; similar results were obtained for serum progesterone levels >2.5 ng/ml. Then, we choose a progesterone level at 1.5ng/ml, 2.0 ng/ml and 2.5 ng/ml as cut-off points to verify this result. We found that the TQE rate was significantly different (P <0.05) between serum progesterone levels < 2.0 ng/ml and >2.0 ng/ml. In conclusion, the results of this study clearly demonstrated a negative effect of elevated progesterone levels on the day of hCG trigger, on TQE rate, regardless of the basal FSH, the total gonadotropin, the age of the woman, or the time of ovarian stimulation. These data demonstrate that elevated progesterone levels (>2.0 ng/ml) before oocyte maturation were consistently detrimental to the oocyte.

The active moiety of clozapine, the prototypical antipsychotic drug, consists of clozapine and its major metabolite, N-desmethylclozapine (NDMC). Previous studies have suggested that NDMC may be more important than the patent compound itself for the improvement in cognition in patients with schizophrenia treated with clozapine. While the pharmacology of clozapine and NDMC are similar in most respects, NDMC has been shown to be an M 1 muscarinic receptor partial agonist whereas clozapine is an M 1 antagonist in vitro and in vivo. We hypothesized that NDMC may improve cognition by increasing dopamine (DA) and acetylcholine (ACh) release in medial prefrontal cortex (mPFC) via direct stimulation of M 1 receptors, whereas both NDMC and clozapine itself would do so by other mechanisms as well, and that clozapine would inhibit the M1 agonist effect of NDMC. In the present study, using microdialysis in awake, freely moving rats, we found that NDMC at doses of 10 and 20, but not 5 mg/kg, significantly increased DA and ACh release in the mPFC and HIP, but not in the nucleus accumbens (NAC). The M 1 -preferring antagonist, telenzepine (3 mg/kg), completely blocked NDMC (10 mg/kg)-induced increases in cortical DA and ACh release. Clozapine (1.25 mg/kg), which by itself had no effect on DA or ACh release in the cortex, blocked NDMC (10 mg/kg)-induced ACh, but not DA, release in the mPFC. The 5-HT 1A receptor antagonist, WAY100635 (0.2 mg/kg) blocked NDMC (20 mg/kg)-induced cortical DA but not ACh release. These findings suggest that: (1) NDMC is an M 1 agonist while clozapine is an M 1 antagonist in vivo; (2) M 1 agonism of NDMC can contribute to the release of cortical ACh and DA release; (3) NDMC, because of its M 1 agonism, may more effectively treat the cognitive impairments observed in schizophrenia than clozapine itself; and (4) M 1 receptor agonism may be a valuable target for the development of drugs that can improve cognitive deficit in schizophrenia, and perhaps other neuropsychiatric disorders as well.

Background: The current study aimed to investigate the impact of asymptomatic or mild severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection on female fertility and laboratory and clinical outcomes in assisted reproductive technology (ART) treatments. Methods: Patients undergoing ART treatments in the Reproductive Medicine Center, Tongji Hospital, Wuhan, from May 2020 to February 2021 were enrolled. Seventy of them were positive for serum SARS-CoV-2 antibodies (IgG and/or IgM), and 3973 patients had negative results. Propensity score matching with a ratio of 1:3 was performed, and there were 65 females in the case group and 195 females in the control group. Findings: The ovarian reserves and ovarian responses between groups after matching were similar. The proportions of mature oocytes, damaged oocytes, fertilized oocytes, cleavage embryos, high-quality embryos, and available blastocysts were also similar, despite a slight decrease in the blastocyst formation rate in the case group. In addition, there were no significant differences in terms of the biochemical pregnancy rate, clinical pregnancy rate, early miscarriage rate, or implantation rate. Interpretation: There is no evidence that a history of asymptomatic or mild SARS-CoV-2 infection in females may negatively affect female fertility, embryo laboratory outcomes, or clinical outcomes in ART treatments.